The present invention relates to improvements in electrophoresis plates and methods of making such plates. By way of background, electrophoresis is a well-established method for separation of biochemicals, and is useful in the analysis of proteins found in complex physiological fluids and tissue. Typically, electrophoresis is carried out in a separation medium, for example a polymer gel such as agarose or polyacrylamide. Of course, cellulose acetate is also used as a separation medium.
In the formation of the electrophoresis plates, the electrophoretic or polymer gel is cast in molds and secured to an inert substrate. In the electrophoresis process, numerous samples are typically placed on the electrophoretic medium, i.e., the polymer gel. To effect the electrophoretic separation, an electric field is established with respect to the gel containing the samples. One common practice has been to immerse the opposite ends of the electrophoresis plate into reservoirs of electrically conductive buffers which are provided to maintain the pH of the electrophoresis process. The buffers are connected to electrodes, the electrodes are connected respectively to the positive and negative terminals of a power supply, and this establishes a voltage gradient across the electrophoresis plate. In response to the voltage gradient, the molecules in the samples migrate across the electrophoretic medium in proportion to various factors such as the charge and size of the protein molecules. All of the foregoing is, of course, well-known.
Rather than immersing the ends of the electrophoresis plate into the buffers an alternate technique has been developed known as "wicking" in which an absorbent wick or piece of paper is used to connect each buffer to its respective end of the electrophoresis plate. This technique is also conventional.
When the electrophoretic separation has been completed, it is typical to place the electrophoresed sample under ultraviolet light. Normally, the gel (such as agarose gel) is essentially colorless, the inert plastic (typically polyester) or glass substrate is transparent, and a piece of dark or black paper is placed under the substrate such that the fluorescence of the sample would be visible. Thus optical contrast was provided by the dark paper such that the results of the electrophoresis could be more easily determined and interpreted.
The present invention provides numerous benefits with respect to the electrophoresis plate and the method of making and using the same, as will be hereinafter described.